The project aims to study biological macromolecular structures using image processing of electron micrographs. Our principal project is concerned with the study of membrane proteins. Efforts are being made to generate regular arrays of the Na ion-K ions ATPase extracted from outer medulla of dog kidney and preliminary results indicate that this may indeed be possible. In a second project we are attempting to determine the structure of the Sendai virus nucleocapsid and the proteolytically modified derivatives of it.